Two of the fastest men in history over 100 metres have failed drugs tests.
Former world champion Tyson Gay says he feels let down by somebody "he put his trust in" after a sample taken in May tested positive.
CONTINUE READING BELOW
Gay has set the fastest 100m time so far this year.
Asafa Powell has also failed a test, along with his Jamaican team-mate and Olympic relay silver medallist Sherone Simpson.
The pair were found to have a banned stimulant in their system at last month’s national trials.
Powell remains adamant that he is not a cheat.